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post-reload life vs scheduling
- To: egcs-patches at cygnus dot com
- Subject: post-reload life vs scheduling
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Wed, 28 Oct 1998 00:19:31 -0700
- Reply-To: law at cygnus dot com
I've installed this patch which should fix many of the bad interactions between
the post-reload life analysis pass and instruction scheduling. It should
fix our sparc problems (including the complex failures) as well as another
handful of sh build failures.
* final.c (cleanup_subreg_operands): New function.
(final_scan_insn): Use it.
(alter_subreg): Clear the "used" field when we turn a SUBREG into
a REG.
* reload1.c (reload): Delete CLOBBER insns and also cleanup SUBREG
operands when reload has finished.
* reload.h (cleanup_subreg_operands): Declare..
* flow.c (life_analysis_1): No longer delete CLOBBER insns after
reload. Handled in reload itself.
Index: final.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/final.c,v
retrieving revision 1.159
diff -c -3 -p -r1.159 final.c
*** final.c 1998/10/09 23:02:32 1.159
--- final.c 1998/10/28 07:15:27
*************** final_scan_insn (insn, file, optimize, p
*** 2933,2955 ****
insn_code_number = recog_memoized (insn);
insn_extract (insn);
! for (i = 0; i < insn_n_operands[insn_code_number]; i++)
! {
! if (GET_CODE (recog_operand[i]) == SUBREG)
! recog_operand[i] = alter_subreg (recog_operand[i]);
! else if (GET_CODE (recog_operand[i]) == PLUS
! || GET_CODE (recog_operand[i]) == MULT)
! recog_operand[i] = walk_alter_subreg (recog_operand[i]);
! }
!
! for (i = 0; i < insn_n_dups[insn_code_number]; i++)
! {
! if (GET_CODE (*recog_dup_loc[i]) == SUBREG)
! *recog_dup_loc[i] = alter_subreg (*recog_dup_loc[i]);
! else if (GET_CODE (*recog_dup_loc[i]) == PLUS
! || GET_CODE (*recog_dup_loc[i]) == MULT)
! *recog_dup_loc[i] = walk_alter_subreg (*recog_dup_loc[i]);
! }
#ifdef REGISTER_CONSTRAINTS
if (! constrain_operands (insn_code_number, 1))
--- 2933,2939 ----
insn_code_number = recog_memoized (insn);
insn_extract (insn);
! cleanup_subreg_operands (insn);
#ifdef REGISTER_CONSTRAINTS
if (! constrain_operands (insn_code_number, 1))
*************** output_source_line (file, insn)
*** 3128,3133 ****
--- 3112,3160 ----
}
}
+
+ /* For each operand in INSN, simplify (subreg (reg)) so that it refers
+ directly to the desired hard register. */
+ void
+ cleanup_subreg_operands (insn)
+ rtx insn;
+ {
+ int insn_code_number, i;
+
+ /* Ignore things we can not handle. */
+ if (GET_RTX_CLASS (GET_CODE (insn)) != 'i'
+ || GET_CODE (PATTERN (insn)) == USE
+ || GET_CODE (PATTERN (insn)) == ADDR_VEC
+ || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
+ || asm_noperands (PATTERN (insn)) >= 0)
+ return;
+
+ /* Try to recognize the instruction.
+ If successful, verify that the operands satisfy the
+ constraints for the instruction. Crash if they don't,
+ since `reload' should have changed them so that they do. */
+
+ insn_code_number = recog_memoized (insn);
+ insn_extract (insn);
+ for (i = 0; i < insn_n_operands[insn_code_number]; i++)
+ {
+ if (GET_CODE (recog_operand[i]) == SUBREG)
+ recog_operand[i] = alter_subreg (recog_operand[i]);
+ else if (GET_CODE (recog_operand[i]) == PLUS
+ || GET_CODE (recog_operand[i]) == MULT)
+ recog_operand[i] = walk_alter_subreg (recog_operand[i]);
+ }
+
+ for (i = 0; i < insn_n_dups[insn_code_number]; i++)
+ {
+ if (GET_CODE (*recog_dup_loc[i]) == SUBREG)
+ *recog_dup_loc[i] = alter_subreg (*recog_dup_loc[i]);
+ else if (GET_CODE (*recog_dup_loc[i]) == PLUS
+ || GET_CODE (*recog_dup_loc[i]) == MULT)
+ *recog_dup_loc[i] = walk_alter_subreg (*recog_dup_loc[i]);
+ }
+ }
+
/* If X is a SUBREG, replace it with a REG or a MEM,
based on the thing it is a subreg of. */
*************** alter_subreg (x)
*** 3161,3166 ****
--- 3188,3196 ----
#else
REGNO (x) = REGNO (y) + SUBREG_WORD (x);
#endif
+ /* This field has a different meaning for REGs and SUBREGs. Make sure
+ to clear it! */
+ x->used = 0;
}
else if (GET_CODE (y) == MEM)
{
Index: reload1.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/reload1.c,v
retrieving revision 1.196
diff -c -3 -p -r1.196 reload1.c
*** reload1.c 1998/10/23 05:53:04 1.196
--- reload1.c 1998/10/28 07:15:40
*************** reload (first, global, dumpfile)
*** 1233,1248 ****
}
/* Make a pass over all the insns and delete all USEs which we inserted
! only to tag a REG_EQUAL note on them. Also remove all REG_DEAD and
! REG_UNUSED notes. */
for (insn = first; insn; insn = NEXT_INSN (insn))
if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
{
rtx *pnote;
! if (GET_CODE (PATTERN (insn)) == USE
! && find_reg_note (insn, REG_EQUAL, NULL_RTX))
{
PUT_CODE (insn, NOTE);
NOTE_SOURCE_FILE (insn) = 0;
--- 1233,1249 ----
}
/* Make a pass over all the insns and delete all USEs which we inserted
! only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED
! notes. Delete all CLOBBER insns and simplify (subreg (reg)) operands. */
for (insn = first; insn; insn = NEXT_INSN (insn))
if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
{
rtx *pnote;
! if ((GET_CODE (PATTERN (insn)) == USE
! && find_reg_note (insn, REG_EQUAL, NULL_RTX))
! || GET_CODE (PATTERN (insn)) == CLOBBER)
{
PUT_CODE (insn, NOTE);
NOTE_SOURCE_FILE (insn) = 0;
*************** reload (first, global, dumpfile)
*** 1259,1264 ****
--- 1260,1268 ----
else
pnote = &XEXP (*pnote, 1);
}
+
+ /* And simplify (subreg (reg)) if it appears as an operand. */
+ cleanup_subreg_operands (insn);
}
/* If we are doing stack checking, give a warning if this function's
Index: reload.h
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/reload.h,v
retrieving revision 1.39
diff -c -3 -p -r1.39 reload.h
*** reload.h 1998/10/17 08:31:26 1.39
--- reload.h 1998/10/28 07:15:41
*************** extern void setup_save_areas PROTO((void
*** 338,340 ****
--- 338,343 ----
/* Find the places where hard regs are live across calls and save them. */
extern void save_call_clobbered_regs PROTO((void));
+
+ /* Replace (subreg (reg)) with the appropriate (reg) for any operands. */
+ extern void cleanup_subreg_operands PROTO ((rtx));
Index: flow.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/flow.c,v
retrieving revision 1.145
diff -c -3 -p -r1.145 flow.c
*** flow.c 1998/10/24 03:33:42 1.145
--- flow.c 1998/10/28 07:15:47
*************** life_analysis_1 (f, nregs)
*** 1340,1362 ****
if (reload_completed)
bcopy (regs_ever_live, save_regs_ever_live, (sizeof (regs_ever_live)));
- /* Also remove all CLOBBER insns after reload. They can cause us to think
- a value is dead when it really is not dead. */
- if (reload_completed)
- {
- rtx insn;
-
- for (insn = f; insn; insn = NEXT_INSN (insn))
- {
- if (GET_CODE (insn) == INSN
- && GET_CODE (PATTERN (insn)) == CLOBBER)
- {
- PUT_CODE (insn, NOTE);
- NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
- NOTE_SOURCE_FILE (insn) = 0;
- }
- }
- }
bzero (regs_ever_live, sizeof regs_ever_live);
/* Allocate and zero out many data structures
--- 1340,1345 ----